CONTRIBUTIONS TO THE BIOLOGY OF RHIZOBIA. VY. 
THE ISOLATION AND CULTIVATION OF RHIZOBIA 
IN ARTIFICIAL MEDIA. 
ALBERT SCHNEIDER. 
Ir is with a somewhat guilty conscience that this paper is sub- 
mitted. It is directly prompted by the fact that numerous inquiries 
have been received as to details regarding the isolation and cultiva- 
tion of the root nodule microbe of leguminous plants. While I am 
now well satisfied that rhizobia are very easily isolated and grown 
in artificial culture media, I am nevertheless only too conscious of 
my earlier repeated failures and mistakes, and the failures of others. 
These facts should have prompted me to publish the finally success- 
ful efforts as soon as possible in order to assist and simplify the work 
of others who were contemplating research along similar lines. In 
a recent article by GRosVENoR,? outlining some rhizobia culture 
work done by Dr. Grorce T. Moore of the Department of Agn- 
culture, the statement is made that “‘after much labor he (Moore) 
isolated the nitrogen-fixing bacteria,” from which we are led to con- 
jecture that even at this late date similar difficulties were encountered. 
With perhaps the one exception of Miss Dawson, so far as can be 
ascertained, no investigator has published a detailed description of 
the methods of procedure in the isolation and cultivation of rhizobia. 
It is then with the view of correcting this neglect that this pape . 
submitted. 
The rhizobia of the various leguminous plants,exa 
and cultivated by the writer, such as those of red clover, : 
bur clover, sweet clover, garden peas, and alfalfa, gave peach 
the same results so far as methods were concerned. The 
difficulties and failures were due entirely to ignorance with re 
to the behavior of these organisms in artificial media, as has with 
set forth in previous papers. However, in spite of the readiness 
in pre- 
which rhizobia are cultivated, the student must observe ae P 
A remarkable discover? 
(October). 1994 
[ocrose® 
mined, isolated, 
white clover, 
* GROSVENOR, GILBERT H., Inoculating the ground. 
in scientific agriculture. The Century Magazine 68:831-839 
296 
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